Global Patent Index - EP 0647038 A1

EP 0647038 A1 19950405 - Method and apparatus for fading compensation in a radio voice communications system.

Title (en)

Method and apparatus for fading compensation in a radio voice communications system.

Title (de)

Verfahren und Einrichtung zur Fading-Kompensation in einem Funksprachkommunikationssystem.

Title (fr)

Procédé et dispositif pour la compensation d'évanouissement dans un système de communication par voie radio.

Publication

EP 0647038 A1 19950405 (EN)

Application

EP 94306925 A 19940921

Priority

US 12828193 A 19930929

Abstract (en)

An analog radio voice communicator includes a speech encoding system (131,133) that acts in series with normal analog speech processing. Normal corrupted speech is encoded during operation of the radio voice communicator. The signal strength of the incoming speech signal is monitored (by 121). During fades when the signal strength is below a threshold value a fade is recognized and the resultant noise signal remaining is ignored by the speech encoding system. A decoder (135) is included in the communicator and operates in cooperation with the encoder and responds to the fade and for the interval of the fade substitutes reconstructed speech in place of the noise signal. Reconstruction is based on the most likely characteristics of the voice signal wave form to follow the previous actual voice signal. This arrangement uses the filter coefficients generated by linear predictive coding techniques (131) and the excitation vectors (133) developed by excitation analysis to reconstruct the expected speech signal in a synthesis filter (135). <IMAGE>

IPC 1-7

H04B 7/00

IPC 8 full level

G10L 13/00 (2006.01); H04B 7/00 (2006.01)

CPC (source: EP KR)

H04B 7/00 (2013.01 - EP); H04B 7/15 (2013.01 - KR)

Citation (search report)

  • [XA] PROCEEDINGS OF 1992 INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING - ICASSP-92 23-26 March 1992, San Francisco (US)
  • [XA] H.MURAKAMI: "TIME DIVERSITY BY PITCH-SYNCHRONIZED INTERPOLATION", IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, vol. VT-29, no. 4, November 1980 (1980-11-01), NEW YORK US, pages 365 - 370, XP011486793, DOI: doi:10.1109/T-VT.1980.23867
  • [XA] PROCEEDING OF 1985 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS -ICC'85 23-26 June 1985, Chicago (US) NEW YORK (US)
  • [A] W.C.WONG & D.J.GOODMAN: "BLANK AND BURST TRANSMISSION OF DATA OVER ACTIVE SPEECH CHANNELS", ELECTRONICS LETTERS, vol. 24, no. 11, 26 May 1988 (1988-05-26), ENAGE GB, pages 670 - 672, XP000827696, DOI: doi:10.1049/el:19880454

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0647038 A1 19950405; CA 2131136 A1 19950330; JP H07177577 A 19950714; KR 950010408 A 19950428

DOCDB simple family (application)

EP 94306925 A 19940921; CA 2131136 A 19940830; JP 25736394 A 19940928; KR 19940023932 A 19940923